A function applied to (some of) its arguments. If it is not applied to all its argument then it is a "{partial application}". Application is usually written in the form f(x) but some languages such as command-line interpreters and many functional languages use juxtaposition: f x. Lisp places the parentheses around the whole application: (f x).

In mathematics, function application is the act of applying a function to an argument from its domain so as to obtain the corresponding value from its range. In this sense, function application can be thought of as the opposite of function abstraction.

In computer science, partial application (or partial function application) refers to the process of fixing a number of arguments to a function, producing another function of smaller arity. Given a function f \colon (X \times Y \times Z) \to N , we might fix (or 'bind') the first argument, producing a function of type \text{partial}(f) \colon (Y \times Z) \to N .

In mathematics, a function from a set to a set assigns to each element of exactly one element of .; the words map, mapping, transformation, correspondence, and operator are often used synonymously.

An application program (software application, or application, or app for short) is a computer program designed to carry out a specific task other than one relating to the operation of the computer itself, typically to be used by end-users. Word processors, media players, and accounting software are examples.

application program

<programming, operating system> (Or "application", "app") A complete, self-contained program that performs a specific function directly for the user. This is in contrast to system software such as the operating system kernel, server processes, libraries which exists to support application programs and utility programs. Editors for various kinds of documents, spreadsheets, and text formatters are common examples of applications. Network applications include clients such as those for FTP, electronic mail, telnet and WWW. The term is used fairly loosely, for instance, some might say that a client and server together form a distributed application, others might argue that editors and compilers were not applications but utility programs for building applications. One distinction between an application program and the operating system is that applications always run in {user mode} (or "non-privileged mode"), while operating systems and related utilities may run in supervisor mode (or "privileged mode"). The term may also be used to distinguish programs which communicate via a graphical user interface from those which are executed from the command line. (2007-02-02)

application program

An application for employment is a standard business document that is prepared with questions deemed relevant by employers. It is used to determine the best candidate to fill a specific role within the company.

A rich web application (originally called a rich Internet application, or RIA or installable Internet application) is a web application that has many of the characteristics of desktop application software. The concept is closely related to a single-page application, and may allow the user interactive features such as drag and drop, background menu, WYSIWYG editing, etc.